Space heating as a typical example

Imagine an office building with a separate unit on each floor due to undergo complete renovation. The building has a central heating system with a 30-year-old natural gas boiler in the basement, and for each floor a calorimeter and a simple control device for setting the temperature. The initial proposal was to replace the central boiler with a new and more energy efficient version.

Systems thinking extends the scope of this proposal...

• ...from the boiler to the entire heating system, and by extension to the entire building. A systems approach will first define the function of the system, in this case to ensure that the offices have a comfortable temperature for desk work while occupied. Not only does the boiler contribute to this goal, but also the heating control system. A more sophisticated control system regulating the temperature in each room separately, depending on the type of occupation, can reduce the heating demand. Going one step further, the building’s thermal insulation and solar heat gain can be brought into the equation. If the building fabric could be improved during renovation, the heat demand could be reduced even further. Following such a re-formulation of needs, the next question is which system, and which energy carrier, can fulfil these needs in the most efficient way. An electrically driven heat pump combined with low temperature heating elements would probably respond to these needs in a more energy efficient way than the existing system with a natural gas boiler.
• ...from the moment of purchase to the entire life cycle of the heating system. A heat pump has a higher purchase and installation cost than a conventional central heating system, but this additional cost is paid back over time by the lower energy costs. Maximizing the energy efficiency of the heat pump – for instance by reducing the energy losses of the compressor unit and its power cables – can further reduce the life cycle cost of the system.
• ...from the heating system in use to the entire material chain of its components. A heat pump uses more material than a conventional heating system because it requires a more extensive tubing network. The additional environmental impact of producing this material is compensated by the lower greenhouse gas emissions during the use phase of the heating system.
• ...from a pure energy advantage to a general cost benefit analysis of the heating system. In opting for a heat pump, a natural gas connection is no longer needed at the premises, opening up the possibility of simplifying and improving the energy contract. In addition, no further boiler maintenance is needed.

Looking at this example, a systems approach might seem almost self-evident. In practice, several barriers prevent it from being so. The costs and revenues are often split among different parties, the various components of the system could come from different suppliers, and the timing of their installation might not coincide.

More generally, a systems approach to energy efficiency will always be more complex than just replacing individual components with more efficient ones. This inevitably requires an investment of time and effort. In other sections of this website we discuss strategies for dealing with this complexity. One of the key questions is how a mixture of raising awareness, incentives, standardization and regulation can lead to actors taking on the challenge of a systems approach, to both their benefit and that of society in general. Looking at the issue from a more conservative point of view, care should be taken to avoid promoting a systems approach discrediting the entire energy efficiency project for being too convoluted to be practically feasible.